Associations between calcineurin inhibitors and arterial compliance in kidney transplant recipients

Introduction: Several studies have suggested an effect of calcineurin inhibitors on arterial compliance in kidney transplant recipients. We aimed to investigate whether the type of calcineurin inhibitor influences large and small artery compliance in these patients independently of other determinants. Methods: Patients (104 men, 56 women; 124 treated with cyclosporine, 32 with tacrolimus), aged 44.5 +/- 11.0 years (20-69), with kidney graft functioning for 3.7 +/- 2.5 years (0.25-14.2), were studied. Arterial compliance was assessed with the HDI/Pulse Wave CR-2000 System, which estimates large (C1) and small artery (C2) elasticity indices. Blood cell count, serum lipid profile, calcium x phosphate product, concentrations of CRP, total protein and albumin, plasma fibrinogen and glomerular filtration rate were estimated. Multiple linear regression analysis was employed to check for associations between C1, C2 and patients' demographic, clinical and laboratory profiles, including type of calcineurin inhibitor used. Results: Both C1 and C2 correlated positively with body surface area and negatively with age and mean blood pressure. Furthermore, C1 was associated negatively with pulse rate (beta=-0.37; p<0.00001), while C2 was related positively to the interaction term of the current use of tacrolimus x its duration (beta=0.19; p<0.005) and negatively to the simultaneous use of cyclosporine and beta-blocker (beta=-0.18; p<0.003), as well as tacrolimus and low-dose aspirin (beta=-0.24; p<0.0002). Conclusions: Calcineurin inhibitors differentially influence small artery compliance in kidney transplant recipients. Use of tacrolimus appears to improve small artery compliance proportionally to the duration of treatment, but combinations of tacrolimus and low-dose aspirin, as well as cyclosporine and beta-blocker seem to exert a negative influence.